Janusz A. Kozinski

Bio: Janusz A. Kozinski is an academic researcher from Lakehead University. The author has contributed to research in topics: Supercritical fluid & Biomass. The author has an hindex of 48, co-authored 219 publications receiving 8091 citations. Previous affiliations of Janusz A. Kozinski include Keele University & National Institute of Advanced Industrial Science and Technology.

Characterization of North American lignocellulosic biomass and biochars in terms of their candidacy for alternate renewable fuels.

Abstract: The use of lignocellulosic biomass as a renewable energy source is becoming progressively essential. Much attention is focused on identifying suitable biomass species that can provide high energy outputs to replace conventional fossil fuels. The current study emphasizes on some commonly available biomasses in North America such as pinewood, timothy grass, and wheat straw for their usage towards next generation biofuels. Fast pyrolysis of the feedstocks was performed at 450 °C to generate biochars that were further characterized to advocate their energy and agronomic relevance. The biomasses were examined physiochemically to understand their compositional and structural characteristics through analytical approaches such as CHNS (carbon–hydrogen–nitrogen–sulfur), ICP-MS (inductively coupled plasma-mass spectrometry), particle size, FTIR (Fourier transform infrared) and Raman spectroscopy, thermogravimetric and differential thermogravimetric, XRD (X-ray diffraction), and high-pressure liquid chromatography. The chemical composition of feedstocks significantly differed from that of biochars and the variations among feedstock composition were also found to be greater than for biochars. The presence of cellulose, hemicellulose, and lignin along with other organic components were identified in the spectroscopic and chromatographic analysis. The FTIR spectra of biochars showed removal of oxygen- and hydrogen-containing functionalities from feedstocks due to pyrolysis at higher temperature, although retaining certain significant cellulose-derived functionalities. A number of crystallographic phases in the XRD of biomass, ash, and biochars were due to minerals commonly Na, Mg, Al, Ca, Fe, and Mn. ICP-MS of biochars demonstrated substantial amount of alkali elements indicating their compatibility towards soil amendment for restoring degraded soils.

Alcohols as alternative fuels: An overview

Abstract: Due to the phase out of lead in all gasoline grades and the adverse health and environmental effects of MTBE, the synthesis of higher alcohols, particularly ethanol, from synthesis gas has drawn considerable interest. Low molecular weight alcohols such as ethanol have replaced other additives as octane boosters in automotive fuels. Adding alcohols to petroleum products allows the fuel to combust more completely due to the presence of oxygen, which increases the combustion efficiency and reduces air pollution. The presence of alcohols in fuel causes corrosion to metallic fuel system components. In order to make the best use of alcohols as alternative fuels; one can redesign the engine or the vehicle can be redesign or one can blend in one or more additives to the ethanol or methanol to improve its characteristics. Catalytic conversion of synthesis gas to alcohols is advantageous, as this uses various renewable and non-renewable carbon resources. Different catalytic systems can be used for synthesizing higher alcohols from synthesis gas. Depending on the process conditions and the catalyst used, the reaction mechanism varies and the products include primary and secondary alcohols of both normal and branched carbon chains. The present paper includes an overview of the processes and catalysts used depending on the production of specific alcohols, as well as, the reaction mechanisms currently accepted. Transition metal-promoted alkali-modified molybdenum sulphide catalysts are considered to be more attractive to improve CO hydrogenation and for the production of linear alcohols.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Thermochemical biofuel production in hydrothermal media: A review of sub- and supercritical water technologies

Abstract: Hydrothermal technologies are broadly defined as chemical and physical transformations in high-temperature (200–600 °C), high-pressure (5–40 MPa) liquid or supercritical water. This thermochemical means of reforming biomass may have energetic advantages, since, when water is heated at high pressures a phase change to steam is avoided which avoids large enthalpic energy penalties. Biological chemicals undergo a range of reactions, including dehydration and decarboxylation reactions, which are influenced by the temperature, pressure, concentration, and presence of homogeneous or heterogeneous catalysts. Several biomass hydrothermal conversion processes are in development or demonstration. Liquefaction processes are generally lower temperature (200–400 °C) reactions which produce liquid products, often called “bio-oil” or “bio-crude”. Gasification processes generally take place at higher temperatures (400–700 °C) and can produce methane or hydrogen gases in high yields.

Hydrothermal carbonization of biomass: A summary and discussion of chemical mechanisms for process engineering

Abstract: Hydrothermal carbonization can be defined as combined dehydration and decarboxy lation of a fuel to raise its carbon content with the aim of achieving a higher calorific value. It is realized by applying elevated temperatures (180–220°C) to biomass in a suspension with water under saturated pressure for several hours. With this conversion process, a lignite-like, easy to handle fuel with well-defined properties can be created from biomass residues, even with high moisture content. Thus it may contribute to a wider application of biomass for energetic purposes. Although hydrothermal carbonization has been known for nearly a century, it has received little attention in current biomass conversion research. This review summarizes knowledge about the chemical nature of this process from a process design point of view. Reaction mechanisms of hydrolysis, dehydration, decarboxylation, aromatization, and condensation polymerization are discussed and evaluated to describe important operational parameters qualitatively. The results are used to derive fundamental process design improvements. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd